


All That You've Been Waiting For

by withpractice_ff



Series: Our Knuckles are White [1]
Category: Marvel Cinematic Universe, The Avengers (Marvel Movies)
Genre: Collars, M/M, Science Boyfriends, Sexcations, Solving life's problems with science
Language: English
Status: Completed
Published: 2012-09-18
Updated: 2012-09-18
Packaged: 2017-11-14 13:12:44
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,430
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/515585
Author URL: https://archiveofourown.org/users/withpractice_ff/pseuds/withpractice_ff
Summary: <blockquote class="userstuff">
              <p>The Hulk is a cock-block.  Tony has a solution.</p>
            </blockquote>





	All That You've Been Waiting For

**Author's Note:**

> For the [kink meme prompt](http://avengerkink.livejournal.com/9218.html?thread=19320578#t19320578):
> 
> _By the power of SCIENCE!, Tony and Bruce invent a collar that prevents Bruce from Hulking out during sex. Naturally, they celebrate by putting it to use. A lot._
> 
> _Bruce also discovers that he likes to wear the collar sometimes when he’s going about his daily life. Like if it’s a stressful day or he really needs to concentrate in the laboratory. Unexpectedly glimpsing that Bruce is wearing the collar under his normal shirt is a massive, instant turn-on for Tony, both because he associates it with sex and because it gets him in a possessive mood. Bruce may or may not enjoy this side effect of the collar as well._
> 
> _Bonus: Another Avenger notices Bruce’s collar and asks what it’s for._

  


* * *

  


“So I’ve been thinking about your problem.”

Bruce looks up from his microscope and adjusts his glasses, frowning. He can think of about a thousand different things Tony might be referring to, and since this is his lead in, Bruce doesn’t have any context with which to narrow it down. This is what communicating with Tony is like, always. Bruce sighs and asks, “Which problem would that be?”

“The big, green, Hulk-shaped one.”

Bruce’s frown deepens, and he turns his eyes back to his T-cell sample. “Any conclusions?”

“Actually, yes.” He waits a beat, then amends, “Maybe. Very probably.”

Bruce squints into the microscope and then makes a note on the legal pad next to him. He swaps his current slide for another one, adjusts the position of the lens, and hums thoughtfully to himself. It’s when he starts writing again that Tony realizes Bruce isn’t going to prompt him.

“Aren’t you going to ask me what I concluded?” Tony wheedles, coming over to Bruce and leaning against the counter. He pokes Bruce in the bicep for good measure.

“Tony, what brilliant thing have you come up with today,” Bruce deadpans. Tony smiles; he likes when people say he’s brilliant, even when they’re being sarcastic.

“Ta-da!” Tony says, and Bruce has to look up to see what he’s ta-daing about. What he finds is a thin strap of soft brown leather draped over Tony’s open palm, a small metal box affixed beside the clasp.

“I’m not entirely sure what I’m looking at,” Bruce admits.

“The world’s first Hulk Suppression Device. Though I might have to backwards engineer a better name, because I’m sort of love in with the acronym F.I.S.T.” Tony makes a little fisting motion with the hand that’s not holding the collar, but Bruce doesn’t notice, staring at the device.

“It’s a what?”

“Obviously it hasn’t been tested yet, but I’m pretty sure it works since, you know, I’m the one who made it. But I was thinking maybe you and I could go upstairs and try it out?” He wriggles his eyebrows at this, and Bruce is having a hard time following along.

“Upstairs?” Bruce parrots. “It does what?”

Tony sighs, looking a little disappointed; he’s used to Bruce being the one person able to keep up with him. But he likes Bruce, and this is important, so he slows it down: “Allow me to address your uncharacteristically pedestrian questions in order: One, it is a Hulk Suppression Device. Two, upstairs is where the bed is. And three, as the name suggests, it should theoretically prevent you from turning into the Hulk.”

Bruce blinks, and the confusion in his eyes shifts into something that looks a whole lot like hurt, which Tony doesn’t quite understand. This is the perfect solution!

“Tony, I--” He stops, and then the confusion's back, as if he's only now fully processing everything Tony has said. “The bed?”

Tony nods, grinning.

“Tony, did you--” He shakes his head, not sure if he should laugh or-- or he doesn’t know what, so he just goes ahead and laughs. “Did you come up with a way to control the Other Guy just so you could get laid?”

“What did you think I made it for?” Tony asks. “As much as I like the guy, you have to admit he’s been a real cock-block.”

Bruce takes the collar out of Tony’s hand, holding it gingerly between his fingers like he thinks he might break it, or like maybe it will break him. “How does it work?”

“Sedatives,” Tony says easily, and at Bruce’s doubtful look, Tony shrugs. “I’ve been cribbing from your notes. While I acknowledge the merits of further analysis, I thought I’d just jump ahead to the application phase.” Bruce nods absently, staring at the device with that fucking half-frown he’s always wearing that Tony sort of hates. “The F.I.S.T."--and he grins like a twelve year old boy when he says it--"monitors your vitals and as needed releases just enough of the sedative to keep your heart rate below the danger zone. Easy-peasy. Can we go upstairs now?”

“I really don’t think this will work.” Bruce sounds sad, almost. Sad and tired, like this conversation is actually physically taxing for him. “I’ve tried this sort of thing before.”

“Well I mean, if you’re under duress or purposely Hulking out, no, of course it’s not going to work. But it’s not meant to forcibly keep Big Green in check, it’s just supposed to give you the breathing room necessary for having lots of awesome sex with genius billionaires.”

Bruce shakes his head again, letting out a little huff of air that’s probably supposed to be a laugh. “You really designed this just so we can have sex?”

“Yes!” Tony says, as if Bruce is finally getting it. “We can start right now, even.”

And Tony makes to do just that, but Bruce puts a hand on his chest as he moves in, holding him back. “I want to do some testing first.”

“But make-outs as testing is the best part,“ Tony complains. He fidgets under Bruce’s hand, moving imperceptibly closer. “What are you going to do instead, run on a fucking treadmill?”

“The last time we made-out in your bed, I nearly had an incident, “ Bruce reminds him. “It was a stupid risk.”

“A sexy risk,” Tony corrects. “And it was fine; you realized things were going green and stopped it before anything happened. You’re in control, Bruce. You know your limits.”

Bruce sighs, absently worrying the collar between his fingers. The arm holding Tony off slackens, and Tony immediately works this advantage, crowding in on Bruce until he can press their bodies together, skipping his lips across Bruce’s neck. Bruce sighs again, tipping his head back slightly to give Tony better access.

“Please,” Tony breathes against Bruce’s skin. “Wherever you want, however you want, but I want to be there.”

“Okay, okay,” Bruce relents, then gently pushes Tony off of him. Tony, to his credit, allows himself to be pushed. “Give me a few days to think about it.”

  


* * *

  


“So, uh, why a collar?” Bruce asks as Tony fastens the thin band of leather around his neck. It’s snug but comfortably so, though the F.I.S.T. is cold against the back of his neck. Practically speaking, the device is small enough that it could be attached to almost anything. 

“It’s possible this is evidence of a previously undisclosed kink,” Tony admits, rubbing his thumb across Bruce’s skin, tracing the line of the collar. 

Bruce considers this. “While in theory I’m not against trying new things, I just want to remind you that I haven’t had sex in, um, a while, and I may turn into a giant green monster if things get too intense. Soooo...”

“Point taken. Now get on your hands and knees and don’t speak until I tell you to.” Bruce raises one unimpressed eyebrow, and Tony gives him his best shit-eating grin.

It had taken Bruce about five minutes to come up with a scenario in which he would be comfortable testing out the F.I.S.T. with Tony, but he waited another two days before he actually shared his conditions, just because he sort of liked the desperate looks Tony was throwing him when he thought Bruce wasn’t looking.

Now they’re at Tony’s private island, off the coast of Brazil. Tony sent the staff back to the mainland and it’s just the two of them, five miles of ocean between them and civilization.

“So, okay, how do you want to do this?” Tony asks. Bruce shifts closer to Tony on the bed, taking one of Tony’s hands in both of his own, fingers slowly working their way up to Tony’s wrist, slipping beneath his bracelet, feeling his pulse beneath the skin. Tony wears the bracelets for the Mark VIII pretty much all the time now, but that had been one of the conditions, too.

“Just like any other time, I guess. Don’t want to overthink it,” Bruce says, and then as if to drive the point home he kisses Tony suddenly, bringing his hands up to cup Tony’s face. Tony moans softly, leaning into him--he’s so fantastically responsive--his own hands sliding up Bruce’s hips and under his shirt, skirting over the soft planes of his stomach.

“Scoot up,” Tony says against Bruce’s lips. They both linger for a moment, foreheads pressed together, and then Bruce steals a chaste kiss before moving up the bed. He kicks his shoes off as he goes, and Tony takes the opportunity to pull the thin black Sabbath t-shirt he’s wearing up and over his head. 

Bruce is lying flat on his back in the center of the bed when Tony joins him, settling his legs on either side of Bruce’s waist. Bruce looks-- not freaked-out, exactly, but alert, and Tony leans in and whispers, “Relax, buddy,” pressing a wet kiss to Bruce’s ear, and Bruce nods, his hands coming up Tony’s back to pull the other man closer. They stay like that for a long moment, Tony sort of hunched over uncomfortably while Bruce just holds him. Even if the angle’s not great, it’s still sort of pleasant, but Tony is chronically short on patience so it’s not long before his lips find Bruce’s neck with soft, barely-there kisses. Bruce lets out a contented little sigh, and then Tony’s sucking a bruise into the delicate skin at the base of his throat.

Bruce’s hands skim down Tony’s back to rest on his hips, thumbs slipping just under the waist of his jeans. Tony takes this as an encouragement and starts on the buttons of Bruce’s shirt--some horrible, scratchy thing that Bruce won’t get rid of despite the closet full of clothes Tony’s bought him. He tilts his head up to catch Bruce’s lips with his own, and Bruce’s kiss feels a bit out of control, needy and desperate and maybe a little scared. When he’s undone the last button, Tony rests a hand on Bruce’s bare chest, over his heart. It beats hard under his palm.

“Still with me?” Tony asks, leaning back slightly so he can see Bruce’s eyes. Bruce nods, leaning forward to capture Tony’s mouth again. He shrugs out of the shirt before letting his shoulders fall back down on the mattress. Tony pulls the garment out from under him and tosses it over his shoulder carelessly. It doesn’t quite make it to the floor, instead landing somewhere at the end of the bed. He doesn’t notice, immediately leaning back in to kiss Bruce some more, threading his fingers through the dense hair on Bruce’s chest.

This is about as far as they got the last time they tried this. Tony had slid his hand up Bruce’s thigh--hadn’t even made it to the goal yet--and Bruce had abruptly jumped off of him, off of the bed. His eyes had been brown and his skin his own, but Tony hadn’t pushed it, showing an incredible self-control that he expected to be praised for later. He’d coaxed Bruce back into bed and they’d sat up watching _SNL_ until Bruce nodded off.

Tony tries it again now, fingers tracing Bruce’s inseam, and Bruce just moans lowly in the back of his throat when Tony finally, finally palms over his erection. He does it again, this time pressing his other hand again over Bruce’s heart.

“It’s like a friggin’ Bad Brains concert in there. You doing okay? Any word from the F.I.S.T.?”

Bruce nods, tilting his head back into the pillow and letting out a deep breath. He looks frustrated and frightened and turned on, and Tony wants to fuck him so bad, right now. “Nothing yet, but I’ve got to be getting close. What’s the threshold?”

“180bpm,” Tony says, and starts undoing Bruce’s belt. “I’d put you around 170, but I’ve got some plans to kick that up pretty quick.” Then he stops, looking up at Bruce seriously. “You can do this.”

Bruce nods again, closing his eyes. Tony resumes his work, and Bruce lifts his hips so Tony can slide off his pants and underwear in one go. And then Bruce lets out a surprised gasp.

“I, uh, I think that was it,” Bruce says quietly, rolling his neck like he’s trying to work out a kink.

“So I should wait a sec, or I should get back to it?” Tony doesn’t really want to wait, not now that he’s finally seeing Bruce’s long, slim cock flushed hard against his belly. But he can, if he has to. He’s pretty sure he can.

“I think I’m good.”

“Thank god,” Tony breathes, and then immediately drops to exhale hotly against Bruce’s inner thigh. The hair here is thinner than on his calves, but it’s as wiry as everywhere else and Tony enjoys the feel of it beneath his fingers, beneath his lips. 

He sucks wetly at the vee between Bruce’s leg and his balls, and Bruce huffs, “You should have put an LCD on this thing, so we could keep track.”

“Version two,” Tony promises, then sucks the head of Bruce’s cock into his mouth.

“Jesus Christ,” Bruce grits out, a hand immediately flying to the back of Tony’s head, grabbing his hair and holding him still. Tony doesn’t move a goddamn muscle, his heart hammering in his chest as he waits for Bruce to push him away or start turning green or maybe buck up into his mouth. He’d really fucking like for it to be that last one. Bruce lets out another gasp, and Tony for the first time wonders if maybe this isn’t going to work; that’s the second F.I.S.T. injection in as many minutes.

But then Bruce is loosening his grip and murmuring, “Okay, okay,” and Tony slides his lips slowly down Bruce’s shaft, hollowing his cheeks as he reaches the base. He waits a beat, letting Bruce adjust, and then slides back up, circling his tongue around the glands before letting go.

“I cannot tell you how badly I’ve been wanting to do that,” he says, looking up at Bruce and wearing a filthy, filthy grin. “I’ve been jerking it pretty much nightly, thinking about doing that.”

“You could, uh, keep doing it.”

Tony laughs, pleased--pleased with Bruce, for being here and doing this and asking for what he wants; pleased with himself, for being right, as usual. 

“My pleasure.”

And then he dips his head and flattens his tongue against Bruce’s shaft, licking up to the tip and then taking all of it in, moaning a little at the weight of it, how it stretches his lips. Bruce is trembling under him, and curious, Tony reaches up to again lay a hand over Bruce’s heart. Bruce covers that hand with his own, holding it in place, and Tony feels the steady, rapid beating, hovering right around 180. He’s a motherfucking genius.

“Tony, I’m going to--” Bruce breaks off, thrusting up into Tony’s willing mouth. Tony nods, eager, and Bruce lets go in long, slow pulses.

When he’s finished, Tony climbs up his body so they’re face to face, rutting a little against Bruce’s side. They kiss lazily, Bruce a bit too fucked-out to make much of a contribution to the effort, and then Tony says into the crook of his neck, “Tell me I’m a fucking genius.”

“You’re a fucking genius,” Bruce agrees easily.

“Now help me get more naked.”

Bruce laughs and gently pushes Tony off of him so he can start on Tony’s belt while Tony toes off his shoes. Tony shimmies out of his pants, kicking them away and onto the floor, then rolls back on top of Bruce, thrusting gently against the junction of his hip.

“Jesus, I should have made this thing weeks ago,” Tony mutters, and Bruce reaches down between their bodies, closing his hand around Tony’s dick. The resultant moan sounds a lot like relief, and it takes him a second before he continues, “I should have started working on it the second we met.”

“You had other commitments,” Bruce reminds him. “More pressing concerns.”

Tony shakes his head, pushing up into Bruce’s fist. “I could have fucked you in the helicarrier, in the lab, up against the windo--” He’s cut off by another moan as Bruce twists his wrist, and _fuck_ but that feels good.

“It’s still a possibility,” Bruce offers, and Tony shudders against him, just at the thought of it.

“Every time we were in a meeting, I was thinking about crawling under the table, sucking you off...”

Bruce releases his hold on Tony’s cock to bring his hand up to his mouth, dragging his tongue over the palm. Tony whines at the loss of contact, and Bruce shakes his head. “God you’re needy.”

“Come on, come on,” Tony urges, bucking up against Bruce’s hip. Bruce obliges, taking Tony back in his hand. It’s just slick enough now for Tony to glide between his curled fingers, just rough enough for the friction he needs. Bruce tightens his grip and runs his thumb over the head, and that’s enough, Tony’s spilling all over Bruce’s hand and Bruce’s stomach and Bruce.

Tony kisses him, close-lipped and suddenly tired, before rolling off of him. He feels around on the floor for his shirt, uses it to clean up the mess on Bruce’s belly, then collapses next to him on the mattress. Their shoulders are touching and Tony feels pretty fucking fantastic. 

“So?” he asks, turning his head to look at Bruce’s profile.

“I already said you were a genius,” Bruce complains, then says, “Um, I feel a little out of it, but not too bad? Probably some of it’s just, you know.”

“Orgasm?” Tony provides helpfully, wriggling his eyebrows. Bruce rolls his eyes. “How many pricks did it give you? Five’s where it tops out.”

“I think four? I might have lost track, I don’t know. Can we get under the blankets?”

“You’re kinda cute when you’re off your game, Dr. Banner.”

They pull down the blankets and tuck in under the sheets. Tony’s not much of a cuddler except that he totally is, and they end up in a tangle of arms and legs, Tony’s head pressed to Bruce’s chest. Tony tells JARVIS to turn off the lights, and he’s ready to sleep for an hour or so and then hopefully go again, but Bruce is tense against him and his breathing is measured, and Tony can tell he’s having _feelings_. Usually Bruce is on board with the idea that emotions are messy and complicated and better left alone, but then sometimes he’s not and wants to break everything down like variables in an experiment, like if he looks at them hard enough somehow they’ll suddenly start making sense.

“Stop thinking so loud,” Tony says into the dark, his breath ruffling the hairs on Bruce’s chest. “Some of us are trying to sleep.”

“Sorry.” And he sounds like he actually is sorry, which makes Tony feel like a bit of a heel. “I just--”

“I know,” Tony says, cutting him off because he does know, really, but also because Bruce is a little doped up and a little vulnerable, and in such a state he might say something that neither of them is ready to deal with at this particular point in time. Things are really fucking good right now, not just at this exact moment but in general, and Tony doesn’t want them to screw it up by examining things too closely. So he says, “We can talk about it tomorrow, after I’ve fucked you over every flat surface in this house.”

“Such a romantic.”

“You love it.”

  


* * *

  


In the morning, they take it slow and easy, Tony jerking them both in long, leisurely strokes. Bruce is sleepy and pliable, letting Tony do whatever he wants, and he only needs one shot from the F.I.S.T. before he’s spilling onto Tony’s hand and the sheets between them. Tony goes down on him in the shower, even though Bruce is still well within his refractory period. Tony doesn’t care, enjoying the solid weight of Bruce’s half-hard cock on his tongue until Bruce reluctantly pulls him back to his feet. They make-out some instead, and that’s pretty excellent.

Tony sucks Bruce off in the kitchen, interrupting Bruce’s attempt to make something that mostly resembles an omelette, and Bruce returns the favor a little later, when they’re watching an episode of _MythBusters_ that they’ve both seen about a hundred times. They rut against each other like teenagers on the pool table downstairs, and on the solid metal workbench in the lab, and, improbably, on the hood of one of Tony’s ridiculously expensive cars. They don’t hit literally every flat surface in the house, but they make a pretty respectable go at it. By the second day Bruce is just leaving the collar on all the time--after that nerve-wracking first time when he was terrified this whole thing wasn’t going to work, the F.I.S.T. hasn’t given him more than one, maybe two shots per encounter, and a couple of times the sharp prick at his skin never came at all--and sexcations are pretty much the best thing ever, as far as Tony is concerned.

“Sexcations are the best,” he declares aloud. Bruce, curled up in a chair across the room and reading an actual book--made of ink and paper and everything, and Tony didn’t quite get it when Bruce tried to explain the smell of the pages and the crease of the spine, but _fine_ \--nods and makes a vague sound of agreement. Tony waits a beat, just enjoying the way Bruce looks sitting casually in Tony’s living room with that collar still around his neck, then says, “I would really, really like to fuck you.”

Bruce gives him one of those huffing laughs of his, so quiet it’s nearly inaudible, and says, “Let me finish this chapter.”

So Tony impatiently waits for him to finish three more pages, and then they go upstairs to the bedroom. Bruce seems pretty calm for a guy about to have a dick up his ass for the first time in something like a decade, and Tony is comfortable feeling at least partially responsible for that.

“Well you look rather pleased with yourself,” Bruce observes from underneath him, flat on his back on the bed and already most of the way to naked.

“Two weeks ago you jumped out of bed when I touched your _knee_ , and now you’re about to let me put my fingers in your ass.”

“I’m very adaptable,” Bruce offers, wiggling out of his underwear while Tony fishes around in the bedside drawer for some lube.

“And oh how I value your adaptability,” Tony says, pressing one slick finger against Bruce’s opening. Tony can feel that the muscle is taught, and he rubs circles around the tight pucker with the pad of his finger, hoping to help Bruce loosen up. “You want to let me know when you’re ready, or should I just go for it?”

“Whatever you want,” Bruce says, and he still looks calm, sounds calm, but his body is undeniably tense.

“You feel pretty tight.”

“Is that a compliment?” Bruce asks, arching an eyebrow. Tony laughs, feeling good about this and about Bruce and about how close he is to getting to be _inside_ of Bruce. He leans in for a kiss, because he wants one and because he thinks probably it will help things along, and keeps gently massaging the tense muscles at Bruce’s entrance. When the flesh finally starts to give, Tony slips a finger in up to the first knuckle, and they both gasp.

“Alright?”

Bruce nods, then rolls his neck in a way that tells Tony he just got a hit from the F.I.S.T. He pushes down on Tony’s finger, sliding it all the way in, and Tony moans, imaging that tight heat around his cock. It’s going to be so fucking good.

Bruce takes the second finger more easily, and Tony scissors his fingers apart, pushing against all that tension. In response, Bruce makes the most wonderfully lascivious sound Tony’s ever heard, and Tony needs to be inside of him immediately. He slowly removes his fingers, and Bruce _whines_ at the loss, and god, Tony is going to fucking explode.

He lines his erection up with Bruce's entrance, pushing gently against the opening, and he’s able to control himself enough to ask, “Ready?”

“God, yes, now,” Bruce pants, eyes squeezed shut and head tipped back, and Tony doesn’t need to be told twice, pushing into Bruce slowly but steadily, a long, deliberate slide that has them both shaking and breathless. When he’s all the way in, Tony just holds himself there, unmoving, letting Bruce get used the feel of him, until Bruce manages, “Okay, yes,” and brings a hand up to grip at Tony’s arm, and then Tony slides out to the tip and thrusts back in shallowly, gently.

They have to go slow, because Bruce’s heart is a piston under Tony’s palm, spiking whenever Tony connects with his prostate. It’s torturous; Tony wants nothing more than to slam into him as hard as he can, to have them both writhing, to leave them sore and sweaty and exhausted. But it’s glorious, too, forcing Tony to take his time, read Bruce’s face, learn what makes him gasp and what has him clawing at the sheets. Bruce’s hands are everywhere, simultaneously drawing Tony in and pushing him away. It’s intimate, intense, and Tony is glad for the distraction of Bruce’s heartbeat, counting out the space between the beats when he starts feeling like maybe they’re not just fucking, maybe they’re making love.

Bruce comes first--Tony makes sure of it--and when they’re finished they lay side by side in the bed, arms not quite touching, and Tony is sure Bruce is going to say it. And he’s not sure what he’ll do, doesn’t trust himself not to fuck it up.

But Bruce doesn’t say it. He pulls the condom from Tony’s flagging erection, tossing it in the general direction of the trash can, then curls himself around Tony’s side, running his hand up Tony’s chest and pressing a kiss to the bottom of Tony’s chin. 

He doesn’t say it, but his hand resting over Tony’s arc reactor means the same thing.


End file.
